Power control for aerial crop dusting



Aug. 23, 1955 P. J. MAGNUSSON POWER CONTROL FOR AERIAL CROP DUSTING 2Sheets-Sheet 1 Filed June 5 1951 Aug. 23, 1955 P. J. MAGNUSSON 2,715,792

POWER CONTROL FOR AERIAL CROP DUSTING Filed June 5, 1951 2 Sheets-Sheet2 Q0 43 1.9 M A Per 33 Moan usson \NVENTOa 1 QaMMQMdMMdR -Q.Lo vrrvgUnited States Patent POWER CONTROL FOR AERIAL CROP DUSTING Per JohnMagnusson, Uppsala, Sweden Application June 5, 1951, Serial No. 229,934

Claims priority, application Sweden July 15, 1950 I 3 Claims. (Cl.43-147) The present invention relates to a manual control device forcontrolling the flow rate of an insecticidal powder when dusting cropsfrom a low flying aircraft, the powder delivery control being associatedwith the aircraft throttle control handle to permit simultaneousmanipulation by the pilot of both the throttle and powder control whileif L using only one of his hands to obtain independent control of boththe aircraft engine speed and of the rate of powder delivery. Thisleaves the other hand of the pilot completely free for the manipulationof other controls.

Means for powder-ing or dusting growing crops from aeroplanes forprotection against noxious insects are known. Such means generallyconsist of one or more containers for the powder, said container beingplaced inside or outside the aeroplane, the powder being fed from saidcontainer to a spreader or nozzle.

For feeding the powder it is known to use mechanical feeding means, forinstance a screw conveyor, or aerodynamical feeding means, which bymeans of the airstream produce a vacuum at the discharge opening of thecontainer, whereby the powder is exhausted from the container.

The powdering from aeroplanes must take place from a very low height,viz. a height below power-lines and the like. -It is evident that thepilot under such circumstances must concentrate his entire attention onthe manoeuvring of the aeroplane.

This requires the pilot, while flying at such low altitudes, to keep onehand continuously on the throttle for effecting frequent changes inengine speed and to keep the other hand free for the manipulation ofother controls. Moreover, it is necessary to control the flow rate ofthe insecticide and to start and stop the flow when entering and leavingthe area being dusted. Unless the powder flow is carefully controlled,insecticidal powder will be wasted or the desired area will be onlypartially dusted,

or both.

Generally, the present invention provides means for controlling the flowof the insecticidal powder, this control means being so combined withthe throttle lever that the pilot can control the flow of powder withoutremoving his hand from the control handle of the throttle lever.

An embodiment of the invention is illustrated in the accompanyingdrawings.

Referring to the drawing:

Figure 1 is an elevational view of a powder reservoir and spreader,partly broken away to illustrate details of construction.

Figure 2 is a plan sectional view of the reservoir and spreader takenalong the line II-II of Fig. 1.

Figure 3 is a front elevational view of a throttle handle embodying theinvention, the handle being shown partly in section and being adaptedfor manipulation by the left hand of a pilot.

Figure 4 is a left end view of the handle shown in Fig. 3.

Figure 5 is a right end view of the handle shown in Fig. 3.

2,715,792 Patented Aug. 23, 1955 In the drawings 1 designates a powdercontainer provided with two discharge duets 2 leading to aerodynamicspreader 3.

Said spreader 3 is constructed according to the venturi tube principle.A straight wall 4 defines the upper part of a channel 5, the bottom ofwhich consists of the upper part of a wing-profiled surface 6, whereasthe side walls of the channel consist of plane surfaces 7.

The uppermost part of said surface 6 is situated beneath said dischargeducts 2, at the throat of the venturi tube, a vacuum thus being producedbelow said ducts 2, when in flight causing the powder to be withdrawnfrom the container 1.

The discharge duets 2 are provided with butterfly valves .3 3, which arepivotably mounted on a horizontal shaft 9.

Said shaft is provided with a lever (not shown) which can be actuated bymeans of a bowden wire 10 (Figs. 4 and 5) for opening and closing thebutterfly valves 8.

In Fig. 3, 11 designates the throttle lever of the aircraft, on which isrotatably mounted a butterfly valve control lever 12, to which thebowden wire 10 is fixed. On the valve control lever 12 a hollowcylindrical sleeve 13 is fixed by welding, the sleeve 13 forming thehandle or operating member for the throttle lever 11 as well as beingrotatable about its own axis for control of the but tertly valves 8.Around the cylindrical handle or sleeve 13 is disposed a length ofrubber tubing 14 for obtaining a better grip of the handle 13. Thethrottle lever 11 is operated by displacing the handle 13 in thedirection of flight which is laterally to the left or right as viewed ineither, Fig. 4 or 5, whereas the flap valves 8 are operated by rotatingthe handle 13 about its own longitudinal axis.

The valve control lever 12 is provided with a circular lower portionconcentric with the longitudinal axis of the cylindrical handle .13. Theupper portion of valve control lever 12 moves between the position shownin full lines and the position shown in dotted lines in Figs. 4 and 5.At its outer or upper end, the valve control lever 12 is bent back toprovide an inverted U-shaped portion, and a transversely extendingradial slot is formed therein, the slot extending across the entireclosed end portion of the inverted U. The legs of the inverted Upartially embrace the movable element of the bowden wire 10 and atransverse pin fixed to the movable element of the bowden wire 19 isreceived in the radial slot, as shown in Figs. 3, 4 and 5.

A plunger 15 extends through the center of the hollow cylindrical handle13 and is axially movable therein. At its left end, as viewed in Fig. 3,the plunger 15 carries a yoke member 16. The yoke member 16, in turn,carries a pair of pins 17 which extend freely longitudinally movablythrough suitable apertures in throttle lever 11 to engage diametricallyopposed locking holes 18 formed in valve control lever 12 near theperiphery of its circular portion. For simplicity of illustration, onlyone locking hole 18 of each of two pairs of holes has been shown inFigs. 4 and 5 of the drawing, and these serve to lock the valve controllever either in the position shown in solid lines or in the positionshown in dotted lines. The plunger 15 is freely slidable throughthrottle lever 12 and valve control lever 13, but is prevented fromrotating with respect to throttle lever 11 by lateral engagement betweenthe pins 17 of yoke member 16 and the sides of the apertures in throttlelever 11 through which these pins pass slidably. As shown in Figs. 3 and4, the valve control lever may be locked in either the position shown infull lines or in the position shown in dotted lines.

The plunger 15 carries a collar 19 intermediate its ends. A helicalcompression spring 20 is wound around the left portion of plunger 15 andbears against collar 19, yieldingly urging plunger 15 to the right asviewed in Fig. 3. At its right hand end, the plunger 15 is provided witha push button 21. Pressure on button 21 unlocks valve control lever .12by disengaging pins 17 from the locking holes 18 and thus permitsrotation of handle 13 about its own axis to open or close the butterflyvalves 8 by means of bowdenrwire 10. Movement of handle 13 to vary theengine speed flexes the bowden wire 10, but does not produce relativerotary movement between handle 13 and throttle lever 11. When pins 17are engaged in locking holes 18, such movement is positively prevented.

I The operation of the device above described is as follows;

During flight the pilot has his left hand on the handle 13, 14 andcontrols the throttle lever by displacing it forwards and backwards inthe direction of flight. Thus, the pilot is able to control thebutterfly valves 8 with the same hand, as the throttle lever, by atfirst pushing the bottom 21, thereby releasing the locking means 16, 17,18 against the action of the spring 20, whereupon the handle 13, 14 isturned, whereby by means of the lever 12 and the bowden wire 10 theposition of the flap valves can be regulated.

i The invention is not limited to the embodiment now described, but canbe modified in several ways within the scope of the invention.

Having now particularly described the nature of my invention and themanner of its operation what I claim 1. A control device for cropdusting apparatus of the class described, comprising: a powder reservoiradapted to be carried by an engine driven aircraft; spreading meansdisposed in the airstream of said aircraft while in flight, saidspreading means being connected to said reserv'oir to receive powdertherefrom; a throttle lever adapted to control the engine speed of saidaircraft; a handle member for manually displacing said throttle lever,said handle member being secured to said throttle lever for rotationwith respect thereto; valve means controlling the flow of powder fromsaid reservoir to said spreading means; and valve control means coupledto said handle 3 4 member and said valve means, said valve control meanscausing said valve means to change the flow rate of said powder fromsaid reservoir to said spreading means in response to rotation of saidhandle member with respect to said throttle lever, whereby the pilot ofsaid aircraft varies both the engine speed thereof and controls thespreading of said powder by the use of a single hand.

2. A control device according to claim 1, further comprising manuallyreleasable locking means'carried by said throttle lever and acting onsaid valve control means for holding said valve means locked to providea fixed flow rate for said powder. 1

3. A control device aceording to claim 2, which said handle member is ofhollow cylindrical configuration and is rotatable about its own axiswithrespect to I Q a 7 said throttle lever, and wherein said locking meanscom- 1 prises a manually operable spring pressed plunger axiallydisplaceably disposed within said handle member, a valve control leverhaving a locking hole formed therein, said valve control lever forming apart of said valve control means, said valve control lever beingpivotally mounted on said throttle lever and adjacent to said throttlelever for pivotal movement about the axisof said. handle memher andbeing secured to said handle member for rotary movement therewith; andmovable locking pin means car ried by said throttle lever and engagingsaidlocking-hole for preventing said pivotal movement, said locking .pinmeans being connected to said plunger for disengagement from saidlocking hole in response to manual pressure on said plunger sufiicientto overcome said spring pressure and withdraw said pin means from saidlocking hole.

References Cited in the file of this patent UNITED, STATES PATENTS GreatBritain Dec. 4, 1940

